Saturday, May 23, 2020

BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, MAY 23, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

FRONTAL PASSAGE THIS MORNING LEFT SOME
RAINFALL, AS WELL AS A TEMPERATURE DROP….

We observed limited visibility due to fog after
a light rain this morning that left only 0.02
inches. Visibility was 20 miles this morning,
decreasing to 10 miles in the afternoon. Wind
was strong, with a max gust of 40 mph. This
was after a wind shift from WNW to ENE. The
temperature dropped from 65F at 7 A.M. to
52F following the frontal passage.

The high so far today is 65F, this is 3 degrees
below the daily normal high of 68F. The low since
midnight is 52F, which is 2 degrees above the
daily normal low of 50F.

Today’s Observations:

7 A.M.
Weather: Broken altocumulus and cirrus
Temperature: 65F; Dew Point: 65F; Relative Humidity: 100%
Wind: WNW at 7 kts
Sea-level pressure: 30.04 ins. Hg: rising steadily
Visibility: 20 miles, distant fog
6-hr Max temp: 61F
6-hr Min temp: 51F
24-hr Precip:  0.02 ins.
24-hr Snowfall: 0.0 ins.
BHO SA 1155 E110 BKN 250 BKN 20 172/65/65/3007/004/ DSNT FG
ALQDS/ 8/072 70002 53009 10065 20063

10 A.M.
Weather: Scattered stratus fractus, broken altocumulus and cirrus
Temperature: 58F; Dew Point: 40F; Relative Humidity: 50%
Wind: ENE at 18G35 kts, peak of 41 mph at 9:20 A.M.
Sea-level pressure: 29.97 ins. Hg: rising, then more rapdily
Visibility: 20 miles, distant fog
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 40 SCT E110 BKN 250 BKN 20 150/58/40/0718G35/997/
DSNT FG ALQDS PK WND 0636/20/ 8/772 53022

1 P.M.
Weather: Broken altocumulus and cirrus
Temperature: 52F; Dew Point: 42F; Relative Humidity: 68%
Wind: SW at 13G27 kts, peak of 33 mph at 12:38 P.M.
Sea-level pressure: 29.92 ins. Hg: falling then rising
Visibility: 10 miles, thin fog
6-hr Max temp: 65F
6-hr Min temp: 52F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E110 BKN 250 BKN 10 134/52/42/0713G27/992/ THN FG
ALQDS PK WND 0729/38/ 8/072 51016 10065 20052

SUMMARY FOR FRIDAY, MAY 22, 2020

TEMPERATURE (DEGREES F)
MAX…..82   NORMAL…..68
MIN…..50   NORMAL…..49
MEAN….66   NORMAL…..59

DEPARTURE FROM 30-YEAR NORMAL………………+7
TOTAL DEPARTURE FOR THE MONTH………………-46 [-2.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………….0  DEPARTURE……..-7
TOTAL HEATING UNITS FOR THE MONTH…………..250  DEPARTURE…….+35
TOTAL HEATING UNITS FOR THE SEASON…………5771  DEPARTURE……-479
TOTAL HEATING UNITS LAST SEASON TO DATE…….6159  DEPARTURE……-388

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………….1  DEPARTURE………0
TOTAL COOLING UNITS FOR THE MONTH…………….3  DEPARTURE……..-8
TOTAL COOLING UNITS FOR THE SEASON……………3  DEPARTURE…….-10
TOTAL COOLING UNITS LAST SEASON TO DATE……….4  DEPARTURE……..-1

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..26 S  AT 12:43 P.M.
AERO…………………….25 S  AT 12:46 P.M.
ASOS…………………….29 W  AT 12:22 P.M.
DAVIS……………………31 W  AT 12:44 P.M. RMY 28
FASTEST MILE FOR YESTERDAY………………….21 W  AT 1:29 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….20 SW AT 6:43 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………22 W  AT 1:29 P.M.
AVERAGE WIND SPEED AND DIRECTION…………….13.9 WSW
ASOS…………………….13.3
DAVIS……………………13.3 WSW [243 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.02  DEPARTURE……-0.12
ASOS…………..0.01
TOTAL PRECIPITATION FOR THE MONTH……….2.55  DEPARTURE……-0.18
ASOS…………..2.54
TOTAL PRECIPITATION FOR THE YEAR……….19.61  DEPARTURE……-1.69
ASOS………….20.15

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..0.0
TOTAL SNOWFALL FOR THE MONTH…………..Trace  DEPARTURE……..0.0
TOTAL SNOWFALL FOR THE SEASON…………..31.9  DEPARTURE……-30.8

PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

05/01  64/52/58/+5/…./0.0/000/00         46 SSE  AERO 44 SSE RMY N/A
05/02  70/42/56/+3/…./0.0/729/86         41 NW   AERO 40 NW  RMY N/A
05/03  78/55/67/+14/0.00/0.0/613/72        35 SSW  AERO 35 SSW RMY 36
05/04  72/45/59/+5/T/0.0/247/29            37 NW   AERO 40 WNW RMY 39
05/05  60/40/50/-4/0.00/0.0/821/96         31 NW   AERO 32 NW  RMY N/A
05/06  57/38/48/-6/T/0.0/498/58            24 ESE  AERO 22 ENE RMY 22
05/07  63/37/50/-5/0.00/0.0/576/67         30 WSW  AERO 29 WSW RMY N/A
05/08  57/40/49/-6/…./0.0/328/38         31 W    AERO 32 W   RMY N/A
05/09  44/32/38/-17/…./T/484/56          52 W    AERO 53 W   RMY 54
05/10  59/31/45/-10/0.00/0.0/763/88        46 W    AERO 46 W   RMY 49
05/11  65/43/54/-2/0.22/0.0/…/..         39 S    AERO 43 S   RMY 41
05/12  55/37/46/-10/0.00/0.0/…/..        37 W    AERO 37 W   RMY 37
05/13  59/32/46/-10/0.00/0.0/…/..        37 WNW  AERO 37 WNW RMY 38
05/14  70/40/55/-2/0.00/0.0/…/..         29 W    AERO 26 W   RMY 27
05/15  78/50/64/+7/…./0.0/…/..         40 WSW  AERO 40 WSW RMY 43
05/16  69/47/58/+1/…./0.0/…/..         31 NW   AERO 31 NW  RMY 32
05/17  67/47/57/0/0.00/0.0/…/..          22 SSW  AERO N/A    RMY 21
05/18  60/47/54/-4/T/0.0/…/..            24 W    AERO 22 ENE RMY N/A
05/19  56/45/51/-7/0.00/0.0/…/..         35 ENE  AERO 34 ENE RMY 32
05/20  63/43/53/-5/0.00/0.0/…/..         22 ESE  AERO 20 SE  RMY 19
05/21  76/42/59/0/0.00/0.0/…/..          26 S    AERO 25 S   RMY 25
05/22  82/50/66/+7/0.00/0.0/…/..         29 W    AERO 29 W   RMY 28

05/23 The low since midnight is 52F, the daily normal low is 50F

DAILY RECORDS FOR MAY 2020

5/13/2020: NEW RECORD LOW OF 32F, REPLACING 35F SET IN
1914 AND 2005

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR MAY 23
HIGH 92F IN 1964,1992
LOW 38F IN 1976
PRECIP 0.97 INS IN 1979
PEAK GUST 49e MPH W IN 1945

RECORDS FOR MAY 24
HIGH 92F IN 1964
LOW 35F IN 1956
PRECIP 2.13 INS IN 1951
PEAK GUST 54 MPH NNE IN 2005

TODAY’S REPORT PREPARED BY: Benjamin Turner